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July 7, 2019  |  

Whole genome sequence and comparative genomics of the novel Lyme borreliosis causing pathogen, Borrelia mayonii.

Borrelia mayonii, a Borrelia burgdorferi sensu lato (Bbsl) genospecies, was recently identified as a cause of Lyme borreliosis (LB) among patients from the upper midwestern United States. By microscopy and PCR, spirochete/genome loads in infected patients were estimated at 105 to 106 per milliliter of blood. Here, we present the full chromosome and plasmid sequences of two B. mayonii isolates, MN14-1420 and MN14-1539, cultured from blood of two of these patients. Whole genome sequencing and assembly was conducted using PacBio long read sequencing (Pacific Biosciences RSII instrument) followed by hierarchical genome-assembly process (HGAP). The B. mayonii genome is ~1.31 Mbp in size (26.9% average GC content) and is comprised of a linear chromosome, 8 linear and 7 circular plasmids. Consistent with its taxonomic designation as a new Bbsl genospecies, the B. mayonii linear chromosome shares only 93.83% average nucleotide identity with other genospecies. Both B. mayonii genomes contain plasmids similar to B. burgdorferi sensu stricto lp54, lp36, lp28-3, lp28-4, lp25, lp17, lp5, 5 cp32s, cp26, and cp9. The vls locus present on lp28-10 of B. mayonii MN14-1420 is remarkably long, being comprised of 24 silent vls cassettes. Genetic differences between the two B. mayonii genomes are limited and include 15 single nucleotide variations as well as 7 fewer silent vls cassettes and a lack of the lp5 plasmid in MN14-1539. Notably, 68 homologs to proteins present in B. burgdorferi sensu stricto appear to be lacking from the B. mayonii genomes. These include the complement inhibitor, CspZ (BB_H06), the fibronectin binding protein, BB_K32, as well as multiple lipoproteins and proteins of unknown function. This study shows the utility of long read sequencing for full genome assembly of Bbsl genomes, identifies putative genome regions of B. mayonii that may be linked to clinical manifestation or tissue tropism, and provides a valuable resource for pathogenicity, diagnostic and vaccine studies.

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July 7, 2019  |  

Genome sequence and comparative pathogenic determinants of multidrug resistant uropathogenic Escherichia coli O25b: H4, A clinical isolate from Saudi Arabia

Escherichia coli serotype O25b:H4 is involved in human urinary tract infections.In this study, we sequenced and analyzed E. coli O25b:H4 isolated from a patient sufferingfrom recurring UTI infections in an intensive care unit at Hera General Hospital inMakkah, Saudi Arabia. We aimed to determine the virulence genes for pathogenesis anddrug resistance of this isolate compared to other E. coli strains. We sequenced and analyzedthe E. coli O25b:H4 Saudi strain clinical isolate using next generation sequencing. Usingthe ERGO genome analysis platform, we performed annotations and identified virulenceand antibiotic resistance determinants of this clinical isolate. The E. coli O25b:H4 genomewas assembled into four contigs representing a total chromosome size of 5.28 Mb, andthree contigs were identified, including a 130.9 kb (virulence plasmid) contig bearing thebla-CTX gene and 32 kb and 29 kb contigs. In comparing this genome to otheruropathogenic E. coli genomes, we identified unique drug resistance and pathogenicityfactors. In this work, whole-genome sequencing and targeted comparative analysis of aclinical isolate of uropathogenic Escherichia coli O25b:H4 was performed. This strainencodes virulence genes linked with extraintestinal pathogenic E. coli (ExPEC) that areexpressed constitutively in E. coli ST131. We identified the genes responsible forpathogenesis and drug resistance and performed comparative analyses of the virulenceand antibiotic resistance determinants with those of other E. coli UPEC isolates. This isthe first report of genome sequencing and analysis of a UPEC strain from Saudi Arabia.

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July 7, 2019  |  

Genome-guided design of a defined mouse microbiota that confers colonization resistance against Salmonella enterica serovar Typhimurium.

Protection against enteric infections, also termed colonization resistance, results from mutualistic interactions of the host and its indigenous microbes. The gut microbiota of humans and mice is highly diverse and it is therefore challenging to assign specific properties to its individual members. Here, we have used a collection of murine bacterial strains and a modular design approach to create a minimal bacterial community that, once established in germ-free mice, provided colonization resistance against the human enteric pathogen Salmonella enterica serovar Typhimurium (S. Tm). Initially, a community of 12 strains, termed Oligo-Mouse-Microbiota (Oligo-MM(12)), representing members of the major bacterial phyla in the murine gut, was selected. This community was stable over consecutive mouse generations and provided colonization resistance against S. Tm infection, albeit not to the degree of a conventional complex microbiota. Comparative (meta)genome analyses identified functions represented in a conventional microbiome but absent from the Oligo-MM(12). By genome-informed design, we created an improved version of the Oligo-MM community harbouring three facultative anaerobic bacteria from the mouse intestinal bacterial collection (miBC) that provided conventional-like colonization resistance. In conclusion, we have established a highly versatile experimental system that showed efficacy in an enteric infection model. Thus, in combination with exhaustive bacterial strain collections and systems-based approaches, genome-guided design can be used to generate insights into microbe-microbe and microbe-host interactions for the investigation of ecological and disease-relevant mechanisms in the intestine.

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July 7, 2019  |  

Origins of the current seventh cholera pandemic.

Vibrio cholerae has caused seven cholera pandemics since 1817, imposing terror on much of the world, but bacterial strains are currently only available for the sixth and seventh pandemics. The El Tor biotype seventh pandemic began in 1961 in Indonesia, but did not originate directly from the classical biotype sixth-pandemic strain. Previous studies focused mainly on the spread of the seventh pandemic after 1970. Here, we analyze in unprecedented detail the origin, evolution, and transition to pandemicity of the seventh-pandemic strain. We used high-resolution comparative genomic analysis of strains collected from 1930 to 1964, covering the evolution from the first available El Tor biotype strain to the start of the seventh pandemic. We define six stages leading to the pandemic strain and reveal all key events. The seventh pandemic originated from a nonpathogenic strain in the Middle East, first observed in 1897. It subsequently underwent explosive diversification, including the spawning of the pandemic lineage. This rapid diversification suggests that, when first observed, the strain had only recently arrived in the Middle East, possibly from the Asian homeland of cholera. The lineage migrated to Makassar, Indonesia, where it gained the important virulence-associated elements Vibrio seventh pandemic island I (VSP-I), VSP-II, and El Tor type cholera toxin prophage by 1954, and it then became pandemic in 1961 after only 12 additional mutations. Our data indicate that specific niches in the Middle East and Makassar were important in generating the pandemic strain by providing gene sources and the driving forces for genetic events.

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July 7, 2019  |  

Complete genome sequence of human pathogen Kosakonia cowanii type strain 888-76T.

Kosakonia cowanii type strain 888-76T is a human pathogen which was originally isolated from blood as NIH group 42. In this study, we report the complete genome sequence of K. cowanii 888-76T. 888-76T has 1 chromosome and 2 plasmids with a total genome size of 4,857,567bp and C+G 56.15%. This genome sequence will not only help us to understand the virulence features of K. cowanii 888-76T but also provide us the useful information for the study of evolution of Kosakonia genus. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

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July 7, 2019  |  

Microbial sequence typing in the genomic era.

Next-generation sequencing (NGS), also known as high-throughput sequencing, is changing the field of microbial genomics research. NGS allows for a more comprehensive analysis of the diversity, structure and composition of microbial genes and genomes compared to the traditional automated Sanger capillary sequencing at a lower cost. NGS strategies have expanded the versatility of standard and widely used typing approaches based on nucleotide variation in several hundred DNA sequences and a few gene fragments (MLST, MLVA, rMLST and cgMLST). NGS can now accommodate variation in thousands or millions of sequences from selected amplicons to full genomes (WGS, NGMLST and HiMLST). To extract signals from high-dimensional NGS data and make valid statistical inferences, novel analytic and statistical techniques are needed. In this review, we describe standard and new approaches for microbial sequence typing at gene and genome levels and guidelines for subsequent analysis, including methods and computational frameworks. We also present several applications of these approaches to some disciplines, namely genotyping, phylogenetics and molecular epidemiology. Copyright © 2017 Elsevier B.V. All rights reserved.

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July 7, 2019  |  

De novo mutations resolve disease transmission pathways in clonal malaria

Detecting de novo mutations in viral and bacterial pathogens enables researchers to reconstruct detailed networks of disease transmission and is a key technique in genomic epidemiology. However, these techniques have not yet been applied to the malaria parasite, Plasmodium falciparum, in which a larger genome, slower generation times, and a complex life cycle make them difficult to implement. Here, we demonstrate the viability of de novo mutation studies in P. falciparum for the first time. Using a combination of sequencing, library preparation, and genotyping methods that have been optimized for accuracy in low-complexity genomic regions, we have detected de novo mutations that distinguish nominally identical parasites from clonal lineages. Despite its slower evolutionary rate compared with bacterial or viral species, de novo mutation can be detected in P. falciparum across timescales of just 1-2?years and evolutionary rates in low-complexity regions of the genome can be up to twice that detected in the rest of the genome. The increased mutation rate allows the identification of separate clade expansions that cannot be found using previous genomic epidemiology approaches and could be a crucial tool for mapping residual transmission patterns in disease elimination campaigns and reintroduction scenarios.

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July 7, 2019  |  

Complete genomic analysis of multidrug-resistance Pseudomonas aeruginosa Guangzhou-Pae617, the host of megaplasmid pBM413.

We previously described the novel qnrVC6 and blaIMP-45carrying megaplasmid pBM413. This study aimed to investigate the complete genome of multidrug-resistance P. aeruginosa Guangzhou-Pae617, a clinical isolate from the sputum of a patient who was suffering from respiratory disease in Guangzhou, China.The genome was sequenced using Illumina Hiseq 2500 and PacBio RS II sequencers and assembled de novo using HGAP. The genome was automatically and manually annotated.The genome of P. aeruginosa Guangzhou-Pae617 is 6,430,493 bp containing 5881 predicted genes with an average G + C content of 66.43%. The genome showed high similarity to two new sequenced P. aeruginosa strains isolated from New York, USA. From the whole genome sequence, we identified a type IV pilin, two large prophages, 15 antibiotic resistant genes, 5 genes involved in the “Infectious diseases” pathways, and 335 virulence factors.The antibiotic resistance and virulence factors in the genome of P. aeruginosa strain Guangzhou-Pae617 were identified by complete genomic analysis. It contributes to further study on antibiotic resistance mechanism and clinical control of P. aeruginosa. Copyright © 2018 Elsevier Ltd. All rights reserved.

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July 7, 2019  |  

Complete genome sequence of Streptomyces formicae KY5, the formicamycin producer.

Here we report the complete genome of the new species Streptomyces formicae KY5 isolated from Tetraponera fungus growing ants. S. formicae was sequenced using the PacBio and 454 platforms to generate a single linear chromosome with terminal inverted repeats. Illumina MiSeq sequencing was used to correct base changes resulting from the high error rate associated with PacBio. The genome is 9.6 Mbps, has a GC content of 71.38% and contains 8162 protein coding sequences. Predictive analysis shows this strain encodes at least 45 gene clusters for the biosynthesis of secondary metabolites, including a type 2 polyketide synthase encoding cluster for the antibacterial formicamycins. Streptomyces formicae KY5 is a new, taxonomically distinct Streptomyces species and this complete genome sequence provides an important marker in the genus of Streptomyces. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

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July 7, 2019  |  

Completed genome sequences of strains from 36 serotypes of Salmonella.

We report here the completed closed genome sequences of strains representing 36 serotypes of Salmonella. These genome sequences will provide useful references for understanding the genetic variation between serotypes, particularly as references for mapping of raw reads or to create assemblies of higher quality, as well as to aid in studies of comparative genomics of Salmonella.© Crown copyright 2018.

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July 7, 2019  |  

Salmonella enterica serovar Enteritidis strains recovered from human clinical cases between 1949 and 1995 in the United States.

Salmonella enterica serovar Enteritidis is one of the most commonly isolated foodborne pathogens and is transmitted primarily to humans through consumption of contaminated poultry and poultry products. We are reporting completely closed genome and plasmid sequences of historical S. Enteritidis isolates recovered from humans between 1949 and 1995 in the United States.

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July 7, 2019  |  

High-quality complete and draft genome sequences for three Escherichia spp. and three Shigella spp. generated with Pacific Biosciences and Illumina sequencing and optical mapping.

Escherichia spp., including E. albertii and E. coli, Shigella dysenteriae, and S. flexneri are causative agents of foodborne disease. We report here reference-level whole-genome sequences of E. albertii (2014C-4356), E. coli (2011C-4315 and 2012C-4431), S. dysenteriae (BU53M1), and S. flexneri (94-3007 and 71-2783).. Copyright © 2018 Schroeder et al.

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July 7, 2019  |  

Complete genome sequence of Escherichia coli 81009, a representative of the sequence type 131 C1-M27 clade with a multidrug-resistant phenotype.

The sequence type 131 (ST131)-H30 clone is responsible for a significant proportion of multidrug-resistant extraintestinal Escherichia coli infections. Recently, the C1-M27 clade of ST131-H30, associated with blaCTX-M-27, has emerged. The complete genome sequence of E. coli isolate 81009 belonging to this clone, previously used during the development of ST131-specific monoclonal antibodies, is reported here. Copyright © 2018 Mutti et al.

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